Roof tile vent for extractor fans

[MortarThePoint]

I'm trying to make up my mind between roof tile vents or wall based extractor fan outlets. It would be the roof option all the way if not for the possibility of condensation being an issue. Does anyone have any experience they can share. I've copied below some pictures of what the roof tile vent looks like (in this case for an SVP vent). I've also copied a very good video about installing such vents. He advocates having a horizontal section to allow any condensation to pool and then evaporate naturally. In many of my instances, the insulation will be at rafter, not ceiling, level but I expect a horizontal length is still a good idea. I probably have an irrational fear of ducting with mould growing on the inside.

 

 

 

 

 

 

[PeterW]

I always try and ensure the pipe runs downward toward the vents and preferably in a rigid pipe. Condensation then will trickle down and not get caught in the ribs or spiral. You’ll get pools of water that will go stale if not.